Acute cigarette smoke exposure alters lungs, liver, and brain histological structures and functions in rats

Abstract

Cigarette smoke contains over 4000 toxic substances known to interfere with physiological processes. While the lungs served as route of  exposure, the liver and brain can also get their share through the circulatory system. This study therefore investigated the acute effect of  exposure to cigarette smoke on the lung, liver and brain of adults male Wistar rats. Fifteen rats (100-120g) were divided into 3 groups as;  group I (control, unexposed rats), with groups II and III exposed to a stick or 10 sticks of cigarette smoke daily for a period of 7 days. At  the end of exposure, rats behavioural assessment was done and the body and organ weights were determined and blood sample taken  for liver enzymes estimation. The organs; liver, lungs and brain, were fixed in 10% formaline for histological processing. Percentage body  weight gain was higher in the cigarette exposed groups and was significant by day 3 compared with the control. Relative weight of the  lungs and lungs tissue GSH were non-significantly decrease while MDA was non-significantly increased in the exposed groups compared  with the control. Serum concentrations of alanine amino transferase, aspartate amino transferase, and alkaline phosphate were  significantly higher in the 10 sticks exposed rats. The duration and number of time spent in open arm was increased while there was  reduced rearing time in cigarette smoke-exposed rats. There was congestion, secretion and emphysematous alveoli space in the lungs  and sign of hepatic injury in the 10 sticks exposed rats while the brain show no sign of distortion. These findings suggest that cigarette  smoke is not without effect on the functions and structures of the organs studied even at acute exposure.